Projectile



W. ULRICH.

PROJECTILE.

APPLICATION FILED SEPT- 4. I920.

Patented Oct. 26, 1920.

gr s'r rs PATENT O-FFHQE.

WILHELM ULRICH, OF ESSEN, GERMANY, ASSIGNOR TO FRIED KRUPP AKTIEN- G-ESELLSCHAFT, OF ESSEN-ON-THE-RUHR, GERMANY.

PROJECTILE.

Specification of Letters Patent.

Patented Oct. 26, 1920.

Application filed September 4, 1920. Serial No. 408,385.

. German Republic, have invented a certain new and useful Improvement in Projectiles, of which the following is a specification.

The invention relates to projectiles fitted with a copper driving band. lVhen projectiles of this kind are fired from a gun. a small portion of the hot powder gases escapes past the driving band and heats the outer layer of the copper up to a point where it becomes comparatively soft, so as to leave a thin film of copper on the wall of the bore of the gun barrel. In course of time, this deposit of copper can under certain circumstances become so considerable as to exercise an unfavorable influence on the movement of the projectile. The invention proposes to remedy this drawback.

The invention will be described with reference to the accompanying drawing which A ring (G) made of tin of the driving band, the outside diameter of the ring (G) being slightly smaller than the diameter ofthe gun-bore measured across the lands.

As experiments have shown, the presence of the tin ring (C) reduces the deposit of copper in the bore to a very slight amount.

This effect is probably due to the tin being vaporized by the hot powder gases surrounding it, whereby the gases escaping past the driving band are deprived of a great part of their heat. The gases, after having beencooled in this manner, are no longer capable of heating the driving hand up to the point where its outer layer is able to form an appreciable deposit of copper on the wall of the gun-bore.

What I claim is: V A projectile having a copper driving band and a ring made of tin arranged in rear of the driving band. The foregoing specification signed at Ger many, this 15th day of June, 1920.

' WILHELM ULRICH. In presence of HANS Go'rTsMANN, Josnr OLBERTZ. 

